<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>控件组</title>
    <link rel="stylesheet" href="../css/bootstrap.min.css">
</head>
<body>
<div class="input-group">
    <span class="input-group-addon">@</span>
    <input type="text" class="form-control">
</div>
</body>
</html>